Your best shot to check filesystem on disks is the lsblk --output NAME,FSTYPE,LABEL,UUID,MODE
It is a list block devices command which will output all your block, hard devices on your machine. With theese option you will get something you want to achieve:
$ sudo lsblk --output NAME,FSTYPE,LABEL,UUID,MODE
NAME FSTYPE LABEL UUID MODE
sda brw-rw----
├─sda1 ntfs WinHyperX 2D6BFC4E0CDCFAD8 brw-rw----
├─sda2 ext4 HyperX ef761208-bab3-4a26-87d2-ed21a7f5a1bb brw-rw----
└─sda3 swap 74259007-a80b-4866-b059-0bdbe6331040 brw-rw----
sdb brw-rw----
└─sdb1 ext4 4TB 91e32977-0656-45b8-bcf5-14acce39d9c2 brw-rw----
sr0 brw-rw----
mmcblk0 brw-rw----
└─mmcblk0p1 exfat 9C33-6BBC brw-rw----
Just to add, if you just simply want to see if there is or not a filesystem on a disk and you dont want to know which or what is it you could also use this command file -s /dev/sda1
or even list fdisk -l
which I think shows all disks and returns error when disk has no filesystem on it.